Charles e



No. 6l7,840. Patented Ian. |7 I899.

c. E. SCRIBNEB. v LOCK-OUT MECHANISM FOR PARTY TELEPHQNE LIN ES.

(Application filed. June 21', 1897.; I 1 (Nu Modei.) I

Witnesses: Invento UNITED STATE onAaL 3s SCRIBNER, or CHICAGO, ILLiNoIs; Assieuoa ro 'rnnfivn'srnnn ELECTRIC COMPANY, or SAME PLACE.

LOCK-OUT MECHANISM FOR PARTY T-ELEPHQNE-LENES.

SPECIFICATION forming part of Letters Patent No. 617,840, dated January 1'7, 1899. I

Application filed Jmie'znisev, shin menses.- a an To all. whom it may concern:

Be it known that 1, CHARLES E. ScRIBNnR, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Lock-Out Mechanism for Party 'lelephone-Lines, (Case No. 450,) of which the following is a full, clear, concise, and exact description, reference being had to to the accompanying drawings, forming a part of this specification.

This invention concerns the mechanism placed at substations of party telephone-lines for preventing interference with the line at '15 one station while the line is in use at another station, The improvementapplies to such so-called lock-out devices in which the line is provided with meansi'or creating current in its conductors continuously during the use of the line, together with a magnet at ehcli station brought into connection with the line through the agency of the telephoneswitch in'taking the telephone for use, the magnet acting to break the circuit of the substation- 2 5 telephone." In lock-out devices of this type difficulty has hitherto been experienced in attaining sufficient quickness of operation in the magnet during the change of position of the telephone switch, the slnggishness of 3c movement of the parts being due largely to the inertia of the armature.

The present invention aims to provide an arrangement of parts such that the movement of the armature prior to theapplication 3 5 of current through the magnet controllin'git is obviated, the armature being placed by suitable mechanical means in contact with its magnet-poles, so that the function of the magnet when traversed by current is merely to" 0 hold the armature in' place when the latter is left free to move in case the magnet is excited lay-current in the line incident to its use.

The invention then consists in the combination-, with the conductor of a party tele- .5 phone-line, a telephone-switch at each station, a magnet at each station-controlling the connection of the telephone at the same station with the line conductor, and means for connecting this magnet with the. line conduco tor in the movement of the telephone-switch,

ct :1 device actuated by the telephone-switch-' mechanism.

a a' fi'or completing the telephone-circuit.

rise of the switch-lever.

when in its normal position for bringing the armature of the magnet into contact with its pole, and means at each station for producing current in the line conductor during the use of the telephone. The invention is illustrated in the attached drawings and may he moreclcarly set forth in connection therewith.

.Of the drawings, Figure 1 representsin side elevation a particular form of my improved lock-out device. Fig. 2 is a plan thereof; and

"Fig. 3 is. a diagram showing the circuits of the party-line, the telephone, and the lock-out In the form of lock-out mechanism herein described the function of looking out the j telephone at any substation is performed by a catch controlled by the look-out magnet and engaging the lever of the telephone-switch to prevent the latter from rising and completing the circuit of the teiephone.

In Figs. land 3 the usual telephone-switch a is represented, comprising a lever a, pivoted at one extremi y of a suitable fixture a andprovided with the usual switch-contacts In addition to these switch-contacts the switch is provided-also with a contactqioint aiwhich is adapted to impinge upon a spring a the same spring serving to impel'thes svitch when relieved of the weight of the telephone as de scribed in Patent No. 425,058, dated April 8, 1890. Associated with this switch-lever is an electromagnct I), provided with an armature I), carried on lever b pivoted at its lower extremity, tending normally to fall away from the magnet. The upper extremity of lever b carries a peculiarly formed catch engaging a pin a in f'lthe switch-lever a and havingtwo' o functions namely, that of pressing the armature-lever forward to bring the armature into contact with the pole-pieces of the mag-c not when the switch isin its lower position and that of engaging the switch-lever when 5 the armature-lever is attracted to prevent the 'lothis end the le ver b is provided with a slot which throughout a portion of its length lies verticaliy in the lever. At a somewhat-higher point it is inclined toward.tl1e magnet, and at a still higher poi at it again extends nearly vertically.

At the u pper endpf .the oblique portion of the slot a recess is formed which permits the metal of the lever to act as a catch for the pin a", which travels in the slot. When the switchlever is in its upper position, thepin allies near the upper extremity of theslot in lever b and the armature b is retracted from the magnet. If the switch-lever be forced downward,-the pin a, traveling in the slot, en'- gages'the oblique portion thereof and advances the armature into contact with the pole-pieces of the magnet. Simultaneously with the reaching of this position by the ar mature the pin enters uponthe second vertical portion of the slot, so that the armature is retained in contact with its magnet as long as the telephone-switch lies init-s lowest position. As the switch rises from this position it permits the armature to remain a moment in contact with its magnet, after which it rises through the oblique portion of the slot and, if the magnet be excited and retain the armature, it impingesupon the. catch formed in the slot and is prevented from further.

of the switch after the pin a has entered the upper vertical portion of the slot: The circuit controlled by contact-pieces a a. is that through the magnet I), while the circuit controlled by contacts a q. is that through the substation-telephone. From this the operation of the device will be apparent, namely: As theswitch begins its upward movement it connects the magnet with the conductor of the telephone-line, after which, if the line he in useahd current be present in it for exciting the magnet b, the magnet will retain its armature and cause the engagement'of, pin

t ed in Fig. 3 extending to two substations and of the switch-lever.

or, preventing the f n rtherupwardmovement 0n the other hand,"if when the contact-pieces a. a. become con nected together no current is present in the line the magnet b will permit the retraction of its armature, and will thus allow the switchlever to rise and complete the circuit of the substation-telephone.

A complete party line-circuit is representterminating at one extremity in switching and signaling apparatus of a telephone-switchboard. The line conductors 1 and 2 of this circuit are led at the central office through av battery 0 and a signaling instrument (2, re-

spectively, to earth. "A spring-jack or con-f nection-socket e constitutes the normally open. terminal of the line in the switchboard. At

each substation a bell f is located in a ground branch from one of the line conductors, the branches being led from different line conductors for the'purpose of maintaining the electrostatic balance of the line conductors. These bells maybe ofthe usual type adapted for operation by alternating currents transmitted from the central oiiice over the proper line conductor. Each substation is further equipped with a receiving-telephone g and a transmitting-telephone g, serially included in a bridge 3 ofthe line-circuit controlled by the switch-contacts a a of a telephone-switch at the same station. The magnet b at each substation is placed in a ground branch 4 from line conductor 2, the completion of the ground branch being determined by the con tact-pieces a a of the telephone-switch. If while the telephone-line is in its normal or idle condition the telephone at either substation be removed from its switch for use, the lever of the switch rising will close first the ground branch at and later the bridge 3 of the line-circuit, thus bringing the telephone into connection with the line for communication. In initiating a call forconnection in the telephone-switchboard this act permits current to flow from battcryc through the bridge 3 to line conductor 2 and thence through the signal (Z in the switchboard, there by calling the attention of the operator.

While the line is in this condition, the source 0 of current is connected with the line con ductor2, in readiness to actuate the look-out mechanism at any other station at which an attempt is made to use the telephone, inasmuch as the upward movement of the switch lever at a second substation immediately closes the ground branch 4; to the line conductor 2, whereby a. current from battery 0 is permitted to flow through the bridge 4 at the substation where the telephone is in use to line conductor 2,thence through the ground branch 4 at the substationin question, ex-

citing. the magnet b and preventing the furthereof in the time elapsing between the closing of swi ch-contacts 5. 6 and switclr contacts 34; b tthe mechanical application of the armature to its magnet prior to the closing-of the circuit through the magnet and the subsequent excitement of the magnet to hold its'armature eliminatethe time consumed'in producing movement of the armature, together with a portion of the time required in charging the magnet, so that the appliance is much more quick and certain in operation than any device heretofore used for this purpose, and is correspondingly eiii: cient. I

I claim as my invention-:-

1. In a lock-out device for a telephone-subei'geee 3 station the eombinetien with s, telegolione-line,

r for producing current in the line duruse of the line, a telephene switeh at e substation, a magnet controlling the circuit 01" the telephone, and switch-contests er" the telephene-switoh adapted to complete the eenneotion of the magnet with the linein the mevement of the switch, of mechanical means eeetro'iied by the switch afiegitefi as bring the. eters of said magnet into contact with its ewwhen the switch its normal posie, substaetieily as rfleseri oed In a leek-out device for teiephones the,

emnbinatioe with a telephone-lineeml means oduein GilliQill; in it thegise of tie, a teiephoneewitoh to dose the tele ie-eircuit, a oetol eclepte. be .prevent the movement of the teieplieneswitch to 2 the teiegmone-eircnit, and a magnet eonlling the s eeteii, switch-contacts closed when the'switch'hes moved throughout its range, other switch-contacts 'oloeeci together.

the switch ie its initial movementeo in the initial movement of the telephone switeh when released, a ceteh .eeptefi toengage the lever of said switch and a magnet controlling the catch, the eonneo'tion of said;

. magnet with the line being controlled through the agency of said leet-meetione switch-eontaote, and a cam centroueil by the switch efiepteri t0 throw the armature into eonzaet with the poles-of itemzgriet', substantially as deseribe.

e, The combination. with a telephoneswiteli, e pivoted lever at right angles to the lever of the ewi-teli, an armature carried by the lever, 212d a magnet controlling the of switch, e cam en the armature-lever eeepteci to engage a progection of the switchlever when the latter is in its lowest yosition afiegited to engage the S'fiZiEGli-lYGl' when the; ermeture is ettreeted to limit the movement to throw the armature int-0 contact with its magnet, and switch-contacts actuated i i the initial movement of the ewitcii closing the circuit of said magnet, substantially as deeoribedin witness whereof I hereunto subscribe my name this eth dey of May, A. D. 1807.

\ CHARLES E. SCRIBNER;

fWitnesses:

ELLA EDLER,

FRANK R, MCBERT'Y. 

